3 stages of cellular respiration:
0. Glycolysis, = It happens in the cytoplasm. It breaks down glucose to pyruvic acid. It does not use oxygen.
,
1. Krebs Cycle, = It happens inside the mitochondria (matrix). It uses pyruvate to produce ATP. Its other names are Tricarboxylic acid and Citric acid cycle. It does not use oxygen but produces carbon dioxide.
,
2. Electron Transport Chain, = It also happens inside the mitochondria (intermembrane space). It uses the NADH and FADH produced from the Krebs Cycle. It also uses oxygen to produce water.
ANSWER: C. Electron Transport Chain only